Transmission system



mnsrmssion SYSTEM.

FILED SEPT 30. l9l8.

UNITEDISTATE Pafen'tedfleb. 20, 1923 PATENT OFF ICE..

HENDRIK J. VAN DER BLTL, O]? NEW YORK, N. Y., ASSIGNOE T0 "WESTERNELEC'IRIC CO1VIIPANY', INCORPORATED, OF NEW Y ORK N. Y., A CORPORATIONOF NEW YORK.

TRNSMISS ION SYSTEM.

York, Sta iae of New York, have invent edcerta1n nqn7 and 'usefulImprovenients in -Transm1ssl on Systems, of which the folloW-.

' ing' iS a full, clear, concise, and exact description. 1

This invention relates t0 a system for the transmission of signals andapparatus necessary thereto. It has for its object to provide anew andimproved syst-em whereby Weak signal currents received ab a station maybesu itably trans formed to a, value sufficient to operate a receivinginstrunient.. In order that this instrument may be operated, even thoughweak Signal currentg are nceived, an

amplifying device, pre ferably a vacuumj tube amplifier, is interposedbetween the rey ceiving instrument and the source f reception 0fweaksignal currents. "There is also interposed betwe'en'ihe amplifyingdevice current shall floW through it that a potensha ll b'e appliecl toit.

and the receiving instrument a controlling devicepermitting the flow 'ofcurrent one direction, nd which requires, in order .that

tial exceeding a certain predetermined value Normallya loca1 source ofcurre1it is applied to this control- 1ing' device which is of -such alueas to be slightly insuifficient to establish a current tbiongh said.d6vice of the"strength neces- .sary to 01gierate themeceivinginstrument. When; .howe"ver, 'wak ignal currents are revcei ved and'amplified, the Voltage eflect of theska currkents .added tq that alreadyestablishqdby the local sriie upon the controlling device, will caus'e acurrent of the proper'yalu'e 110 flovvthrough the receiver. This{ci1rrnt c'ontrolling device may be a 001d eldctrodgap of be prperdimensions, e;' g mercury and irbn electrodes. a'nd having app]ied thereto a potenti al from a 100211 batterygq that norinally the p0tentialacross the gap is insufficient -tostart an am, which arc, however, isstarted whenever the potentia1 ffectof the signalihg currents is addedto that already appli ed. When the efl:'ect of the weak signalin'gc1irrehjss is rmoved, the a1C is stopped because the; loca1 potential isnot large enough t0 maintain it.- The eurrent controlling devi e mayalso be a twoelectrode thermionic devicebomlarising a heated filamexltand having a otential a.p-.

plied thefeto of a-value sufficient-only t0 estaibligh a; currentslightlybelow the value of that required to operate the teceiver. Inthis case, when the Signal current efl'ects are added t0 thoseestablishecl, the' sum of the two is 0f a valne sufficient to operatethe -receiver. The inVention as illustrated in the figure comprises aline l, Which may be anordi'nary telegraph line 01 may be'connectdd t0 as uitable anten'na (nt sh0vvn) for the recept1on of WireIess signzils.This line is qonnected 't0 a receiving station by fiieans of atransfornler 2. In this receiving statio'n is a v aCuum tube amplifyingdevive 3 0f suitable form; comprising one 01 Inore tubes. In circuitWith this vacuun1 tube amplifying device is a receiving instl hment 4shownin the form of a line rel'ay, and interposedbetween this receivinginstrument 4 and the' vacuumfijube amplifying device 3 is a eurrentcontrolling device 5, which in the form shown is a therrnionic devicehaving a heated filame nt 6 and an electrode 7'. Supplied.between thes'eelectrodes from a battery 8 isa- SOUICG 0f potential so a1- r'anged ast0 make the eleCtrode 7 positive. with respect to the filament 6, vandof such value as to pause a thermionic eurrent to flow betweensaidfilament and e1ec-' ti'ode, and 0f a value slightly below that necessa.ry to operatejhe npceiving instru- A 'to maintain an am across thegap, which arc hwever is establishedwhenever signaling eurrentg arereceived and arnplified. The

' am whenestablished canses a unidirectional c'uir'ent of the propervalue to flow through the rece iver 4 and operabe it. When the signa1scease, however, the arc is quenched because the potential remainingacross the gap is insuflicien t to maintain the arc.

*rriable signalcurrent, a receiver adapted saicl receiveroperating underthe m be actuatecl by signal crmnais 0*i prede terminecl value, a threeelectrode vacuurn tube amplilying clevice between saicl receiver analsaidsource, a gap in series Wit-h saicl receiver, ancl a so'urce 015otential appliecl t0 said gap of a value bel0w that required toestablish a space curl'ent across saicl gap of sufiicient value tooperate the receiver.

In a signaling systen1 a source 0f weak variable signal current, alreceiver acla'pted E0 b6actu atecl by Signal current s of apreleterminedvalue, a tlnee electrode vacuum tube amplifier conductively connecteclto said receix*er ancl said source, atl1e1mionic device seriallyintetpnsed between saicl receiver and saicl vacuum tube a1np-lifier,ancl source of otential in circuit Wi1:h said thermionic device 0f avalue sli;rl1tly insufficient t0 establish in said circuit currentnecessary operate. the receiver.

3. In a signaling; system, a Sou1ce of weak "variable signal current, athree-electrode vacuun1 tube f01 am.plifying said currenb, a

signzil-indicating clevice, an l a unidireqt1onal Cu1rent lev1ce 111ser1es w1th sa1d anv plifying device anal Sai l signal-inclicatingdevice.

4. In a Signallng system, a receiver, a source of local. current appliedto said receiver slightly insufficienf; 130 cause its operation, atherrnionic dvice in series wit-h che receiver a sou-rce of Weakvariable Signal currents, a three-electrode vacuurn tnbe amplifierconcluctively connected t0 saic'l receiv'er and said. sou1ce of Signalcurrents, cumulative ourrent action.

5. In a signaling system, a receiver, a source 0f local current applieclt0 said receiver, slightly insufficient to cause its ope'ration, atwoelectrode thermionic device in series .with the receiver, a source 0fWeak variable signal currents, a bhree-electrocle vacuum tube amplifierconductively C011- nected t0 saicl re=ceiver a1id sai l S0urce 0f signalcurrents, said receiver ope1ating under the cum.ulative current action.

- 6. In a signaling system, a s0urce of weak variable signalcurrent,areceiver adaptecl t be actnated b-y signal currents 0f a predeterminedvalue, a three-ele'ctrode vacuum tube amplifying device between saidreceiver and said source, a gap in circuit Witl1 said receiver, and asource of potenfiial appliecl t0 said gap 0f a value below thatrequirecl to establish curre nt saturation in sai l gap and below thatrequired to establish a space current across said gap of sufi1cientvalue t0 operate the receiver.

7. A system comprising a vacuum tube la' ving an anocle, a. caohocleancl a control electrocle, a unidirectional cug1tent nonduct 1ngtherm1on1c deV1ce of the. -wo electrncle type, mans W-l1ereby the-current thniugh saicl device is variecl in aceorclance Witli variationsin the space currenfi 01 said vacui1n t-nbe, ancl a circuit interruptingclevice actuated by the space current 0I saicl twoelec trocl'e device.

8. A System comprising a vacuu1n tube having an anode, a cathoqle and acont-1ol electlode a uniclirectional c'urrent device, means whereby thecurrent through saicl clevice is "aried in acc orclance with variationsin the space surrent 0f said mcuurn tube and an electromagnetic cileuitinterrupting clevice having a winding' in seri es with SHICIuniclirectional cu1rent devive.

9. A syste1n comprising a vacuum tube having an anode, a 'cathode and ac ontrol electrode, a two-electrocle thermionic device f01 transmittingcurrent. waves 0f 0ne sign produced fron1 saicl tube, means whereb'y thespace current 0f said thermionic device is Varied in accordance withvariat ions in the space current 0f said vacuum tube, and anelectron1agnetic circuit interrpting device having a winding in serieswith said ther- 1nionic device, said means including a leacl connectingthe cathocle, of on e 0f said tubes 190 the anode of the otl1er 0f saidtubes.

10. A system comprising a source 0f alternating current, atlnee-electrode 'arnplifier therefor.a unidirectional current conductingdevice; a circuit interrupter having an actuating wincli1ig, and rneans'hereby said amplifier and saicl unidirectional current device jointlycontrol said circuit interrupter,

said 1neans including-leads conneting said winding in series with saidrectifier.

ll. A System comprising a three-electrotle thermionic tube, aunidirectional thernlionic cunent conducting device 01'? the two-electrole type, a circuit interrnpter having a winding in series with saicltwo-electrode cle- \'ice and connections f0r causing thespace current ofsaicl t-wo-electrode device t0- vary in accorclance with variations inthe 'space current of saicl three-electrode tube, said relaybeingdesignecl to have its" armat u1q e rernain in one position when thespace current 0f said tl1reeelectrode tube is ab its normal value anclto be operated t0 its other position when the space current of sa idfirst v2ici1un1 tube increases t0 a priacleterrnined value.

In witness whereof, I hereunto Subsc1ibe my name this 25th day o.fSeptember A. D.,

